Do you mean. Rsd and crps? For all intensive purposes they are pretty much the same with slight difference. A terrible pain syndrome that is often very difficult to treat. Early on it seems intense physical therapy may help. It is good to seek out treatment with docs that have experience with treating this condition.
Updated terminology. Crps(complex regional pain syindrome) is the most recent "formal" term for a group of symptoms that include pain and visible signs (malfunction of autonomic nervous system: swelling, color changes, skin temp differences, etc) that is also called rsd. After an injury, neuropathic pain (google) and this neurological disorder rarely occur. Like many neurologic malfunctions, treatment is difficult.:(.